Windows cannot access \\laptop ... check the spelling.....

I'm having intermittent trouble accessing my Win 8.1 lenovo laptop from other machines on the network. When it doesn't work, the error is:
Windows cannot access \\lenovo-pc ...check the spelling...

When it does work it connects immediately.

The laptop shows up in the left side of the explorer window but throws the error a few seconds after being selected.
If I reboot the router the laptop shares show when selected and everything works as expected for a while then stops and attempting to view shares on the laptop are met with the error.

Tried to connect from a wired win 7 ultimate desktop, a wired win 10 pro desktop, both show same error.